In various processes, it may be necessary or desirable to obtain a temperature profile throughout a vessel. Because of space limitation or cost, it may be impractical to insert individual thermocouples through numerous openings in the vessel to obtain such profile. Therefore, a variety of multipoint thermocouple assembly designs, each of which can be inserted through a single opening in the vessel, have been offered to the public. A protection well (assembly or exterior housing) containing several thermocouples is generally used.
Ideally, the hot (measuring) junction of each thermocouple is in direct contact with the inside wall of the exterior housing for fast response to temperature changes in the process. One method of maintaining this direct contact has involved the use of springs. To the best of Applicant's knowledge, the previous spring methods have included a leaf spring or bimetallic spring, the use of the latter spring being claimed in U.S. Pat. No. 3,015,234. Applicant is unaware of any prior use of coil springs for maintaining the contact between the hot junctions of the thermocouples and the inside wall of the exterior housing.
Applicant presently is aware of the following patent in the field of the art: U.S. Pat. No. 3,015,234 (Springfield, 1962). Applicant also is aware of its own multipoint thermocouple assemblies including the leaf spring design which is shown in Assembly Type II of the enclosed paper.